Modified Thermostat & Water Thermo Switch Field Installation Procedures (83 GLC Only)

STEP 1 Inspecting for previously-installed modified Thermostat and Water Thermo Switch.

1) If the VIN of the vehicle is later than those VIN's below, the modified parts have been installed during production.

JM1BD221 E0750001 JM1BD231 E0750001 JM1BD241 E0750001

2) Look for a white paint mark on the Thermostat Housing and on the Water Thermo Switch. If a white paint mark is present the modified parts have already been installed.

Thermostat Assembly:

Jiggle Pin:

STEP 2 Installation procedures.

1) Drain the coolant.

2) Remove the following parts:

a. Hose

b. Thermostat cover

c. Thermostat

3) Install the modified Thermostat (82~) with the jiggle pin at the top as shown.

4) Install the Thermostat housing using the new gasket.

5) Install the hose.

6) Remove the Water Thermo Switch from the thermostat housing.

7) Install the modified Water Thermo Switch (91~) in the thermostat housing.

8) Fill the cooling system with the proper mixture of coolant.

9) Run the engine and check for leaks.

10) Mark the Thermostat Housing and Water Thermo Switch with white paint as shown in the illustration.